钢框架内嵌ALC双拼板足尺模型振动台试验研究

ALC双拼板是一种新型小尺寸拼接装配式墙板类型，采用角码连接，多用于内隔墙。通过相邻墙面安装有装配式ALC双拼板和条形板的钢框架足尺模型振动台试验，分别对两种板材及其连接件的抗震性能进行对比研究。结果表明：ALC双拼板与条形板这两种围护结构具有基本相同的良好抗震性能；整体围护结构在地震过程中损伤较小，自振频率降低幅度有限，ALC墙板对钢框架的侧向刚度有提高作用；ALC双拼板和条形板的加速度放大系数增加幅度和位移响应均较小，墙板基本处于弹性阶段，未发生明显破坏；角码连接件在地震过程中起到了限位及固定墙板的作用，材料未进入屈服状态。研究结果为装配式ALC双拼板围护结构的工程推广和应用提供了可靠的试验研究依据

高温培养条件下爪哇伪枝藻的生理特性和超微结构特征

荒漠生物结皮广泛分布于干旱区环境,高温是影响生物结皮中藻类生存的重要环境因子。在实验室培养条件下,以生物结皮形成和发育中的重要优势种爪哇伪枝藻(Scytonema javanicum Born et Flah)为材料,研究高温胁迫对伪枝藻生理生化特性和细胞结构的影响。设置了25℃(对照)、35℃、40℃和45℃等不同高温处理,测定了短期(6h)和长期(15d)高温条件下,S.javanicum的光合活性、光合色素、多糖含量和丙二醛含量以及细胞超微结构的变化。结果表明,S.javanicum最大光化学量子产量Fv/Fm和PSII有效光化学量子产量ΦPSII在35℃下表现出最大值。40℃高温明显抑制藻体叶绿素a合成,35℃处理促进了叶绿素a合成(高于对照值),而40℃处理明显促进了藻体类胡萝卜素合成,高于对照处理和35℃处理。随温度升高,S.javanicum丙二醛、胞内可溶性糖和胞外多糖含量呈现出逐渐增大的趋势。透射电镜切片显示,40℃高温明显破坏了藻体细胞超微结构,如原生质体出现絮状形态和空泡化,35℃处理则有利于细胞形态结构的保持和稳定。以上结果初步证实了S.javanicum能够较好地耐受适当的高温(35℃)。研究对于了解S.javanicum对高温环境的耐受程度及对高温的适应性具有一定的理论意义,并对利用荒漠蓝藻治理荒漠化具有实际指导价值

不同悬浮介质对激光衍射法测得的变形指数—渗透压曲线的影响

本文用PBS和PVP两种介质作为激光衍射仪的悬浮介质,系统地观测了悬浮介质物化性能不同对红细胞变形指数(DI)—渗透压曲线的影响,发现:1.在不同悬浮介质中的变形指数—渗透压曲线有显著差别,在高渗区这种差别更明显.2.同一红细胞试样,在相同高渗压下,在不同的悬浮介质中进行交叉实验表明、PBS悬浮介质能使得红细胞变形性得到恢复,而PVP悬浮介质却使得红细胞变形性显著降低.3.在高渗情况下,首次观察到红细胞变形性随时间变化,一开始DI增大,约3小时后趋于稳定,无论PBS还是PVP其趋势皆相似

产量与经济效益共赢的高效生态农业模式:以弘毅生态农场为例

化学物质的大量投入以及元素不能循环导致农田生态系统退化,耕地质量和产量均呈下降趋势,食物链受到污染.本研究从低产田开始,通过秸秆养牛、腐熟牛粪还田恢复地力;以物理+生物方法控制虫害;以人工+机械管理杂草,停用农药、化肥和除草剂,同时不用地膜、人工合成激素、转基因种子生产优质安全食品,并在线上与线下销售.10年的长期实验结果表明,所在村庄农田生态环境改善,减少农药用量58.3%;物理+生物控虫效果明显,每盏灯年捕获量从2009年的33 kg下降到2014年的2.1 kg,下降93.8%;年消耗秸秆1000 t,秸秆利用率从1.1%提高到62.5%.有机肥还田提高了土壤生物多样性,有机果园蚯蚓数量317条m~(-2),而普通果园只有16条m~(-2);大量有机肥还田(75 t hm~(-2)),土壤有机质从实验初期的0.7%提高到2.4%.粮食产量从最初的11.43 t hm~(-2)提高到目前的17.43 t hm~(-2),其中冬小麦(Triticum aestivum)、夏玉米(Zea mays)、大豆(Glycine max(Linn.)Merr.)和花生(Arachis hypogaea Linn.)产量分别超出山东省平均水平42.6%,60.9%,32.2%和38.1%.由于质量好,产品已销售往除西藏以外的30个省、市、自治区,经济效益明显,平均每公顷效益是普通农田的3~5倍,带动所在村庄67户农民从事高效生态农业.本研究可为国家制定生态农业发展规划、精准扶贫、农村环境保护等提供科学依据

Determination of the number of ψ(3686) events taken at BESIII

The number of ψ(3686) events collected by the BESIII detector during the 2021 run period is determined to be (2259.3±11.1)×106 by counting inclusive ψ(3686) hadronic events. The uncertainty is systematic and the statistical uncertainty is negligible. Meanwhile, the numbers of ψ(3686) events collected during the 2009 and 2012 run periods are updated to be (107.7±0.6)×106 and (345.4±2.6)×106, respectively. Both numbers are consistent with the previous measurements within one standard deviation. The total number of ψ(3686) events in the three data samples is (2712.4±14.3)×10^

Prediction of Energy Resolution in the JUNO Experiment

International audienceThis paper presents the energy resolution study in the JUNO experiment, incorporating the latest knowledge acquired during the detector construction phase. The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV. To achieve this ambitious goal, significant efforts have been undertaken in the design and production of the key components of the JUNO detector. Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution, extending beyond the statistical fluctuations of the detected number of photons, such as the properties of liquid scintillator, performance of photomultiplier tubes, and the energy reconstruction algorithm. To account for these effects, a full JUNO simulation and reconstruction approach is employed. This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution. The study reveals an energy resolution of 2.95% at 1 MeV. Furthermore, the study assesses the contribution of major effects to the overall energy resolution budget. This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data taking. Moreover, it provides a guideline in comprehending the energy resolution characteristics of liquid scintillator-based detectors